The present invention relates to a fuel tank disposition structure of a vehicle in which a plurality of passenger seats are disposed longitudinally in a cabin.
Conventionally, the following structure is known as such a fuel tank disposition structure of a vehicle. Namely, there is provided a tunnel portion which projects upward toward an inside of the cabin at a central portion of a floor panel forming a lower face of the cabin in a vehicle width direction. And, there are further provided a central projecting portion which further projects upward from the above-described tunnel portion between a driver seat and a assistant seat, and a pair of side projecting portions which respectively project upward from portions of the floor panel below respective seat cushions of the driver and assistant seats. Herein, the side projecting portions are formed so as to extend in the vehicle width direction between the tunnel portion and side sills, and a fuel tank is disposed below the central projecting portion and the right and left side projecting portions so as to extend in the vehicle width direction (see Japanese Patent Laid-Open Publication No. 2000-85382).
In this conventional structure, since the fuel tank is disposed effectively by utilizing a dead space below the front seat (driver seat and assistant seat), there is an advantage that a roomy cabin can be ensured even for a compact car. However, this structure has a problem that since the fuel tank is disposed so as to extend in the vehicle width direction, some measures against a vehicle side crash may be necessary and protecting the fuel tank with frames enclosing the fuel tank may cause a weight increase of the vehicle.
Generally, by raising the seat cushion of the assistant seat toward the seat back in its upright position and then sliding the seat cushion and the seat back forward together, a space for a luggage or the like can be created at a portion where the assistant seat was located originally. Herein, in the above-described structure, the side projection portions might prevent such a proper luggage space to be created. Thus, this conventional structure has another problem that a proper utilization of space during a seat arrangement of the vehicle may not be attained.
Meanwhile, the following structure is also known as another conventional fuel tank disposition structure. Namely, the tunnel portion which projects upward toward the inside of the cabin at the central portion of the floor panel forming the lower face of the cabin in the vehicle width direction, and there is provided a cover member which is located at substantially the same level as the floor panel so as to cover the lower of the fuel tank. The fuel tank is disposed between the cover member and the tunnel portion so as to extend in the longitudinal direction of the vehicle (Japanese Utility Model Laid-Open Publication No. 59-78131).
In this conventional structure, since the fuel tank is provided in the tunnel portion such that the lower portion of the fuel tank does not project below the floor panel, the height of the fuel tank is apt to be greater in order to ensure a sufficient volume of the fuel tank. Accordingly, this conventional structure may need a relatively large-sized tunnel portion, and it may be difficult to facilitate a walk-through arrangement in the vehicle width direction. Thus, this conventional structure may not be suitable for the compact car particularly, either.